Opened 4 months ago

Closed 3 months ago

#2421 closed help (answered)

UKCA NetCDF aerosol files with Gregorian calendar?

Reported by: nfreychet Owned by: luke
Priority: normal Component: UKCA
Keywords: Cc:
Platform: ARCHER UM Version:



Is there a directory with the gregorian version of all the new netcdf aerosols files required for the ukca scheme on ARCHER? (or MONSOON)

Based on what I found in /projects/ukca-admin/inputs/ancil/gregorian/n96e/ancil_versions/GA7p1_AMIP on MONSOON, I managed to find gregorian netcdf for all the emission files (on MONSOON) except for the oxidant offline. I'm not sure they already exist?
I transferred the files I found to my work space on ARCHER but if they already exist somewhere I could delete my copy, that would save some space.

Also, if the oxidant files have no gregorian version yet, if there an easy way to convert the calendar?
I tried with cdo, for example:

cdo -setcalendar,gregorian

but the problem is some variables are not output (forecast_reference_time, leadtime, …) and I'm not sure what they correspond to?


Change History (4)

comment:1 Changed 3 months ago by willie

  • Component changed from UM Model to UKCA
  • Platform set to ARCHER
  • UM Version <select version> deleted

Hi Nico,

Sorry for the late reply. The standard ancillary files are stored under $UMDIR/ancil on ARCHER and Monsoon. If you need non-standard ancillary files you'll need to create them yourself. If it is a UKCA suite that's involved, then perhaps Luke Abraham could advise.


comment:2 Changed 3 months ago by willie

  • Owner changed from um_support to luke

comment:3 Changed 3 months ago by luke

Looking in


this implies that the Gregorian offline oxidants can be found here:

# directories for netcdf oxidants (used in offline oxidants runs)
export UM_NETCDF_UKCAOXID_O3_DIR=$UM_UKCA_N96EDIR/oxidants/ccmi_refc1_anqdg/clim_1988_2010/v1
export UM_NETCDF_UKCAOXID_OH_DIR=$UM_UKCA_N96EDIR/oxidants/ccmi_refc1_anqdg/clim_1988_2010/v1
export UM_NETCDF_UKCAOXID_NO3_DIR=$UM_UKCA_N96EDIR/oxidants/ccmi_refc1_anqdg/clim_1988_2010/v1
export UM_NETCDF_UKCAOXID_H2O2_DIR=$UM_UKCA_N96EDIR/oxidants/ccmi_refc1_anqdg/clim_1988_2010/v1
export UM_NETCDF_UKCAOXID_HO2_DIR=$UM_UKCA_N96EDIR/oxidants/ccmi_refc1_anqdg/clim_1988_2010/v1

which resolves to here:


However, this directory doesn't exist. I can find the directory


i.e. in $UMDIR. However, these are explicitly

time:calendar = "360_day" ;

so no help there.

The best bet is probably to contact the Met Office. I'll email and see if the correct files can be copied.


comment:4 Changed 3 months ago by luke

  • Resolution set to answered
  • Status changed from new to closed

Mohit has kindly copied the data across to here:


containing the files

These do have the correct calendar now:

time:calendar = "gregorian" ;
forecast_reference_time:calendar = "gregorian" ;

Mohit has highlighted:

Note that these were created by simply modifying the time stamp and calendar type of the 360-day ones. For CMIP6, I think there has been a recent code and attribute change which makes the emissions files (at least) to be calendar independent.

so depending on what model version you are running this may no longer be an issue.


Note: See TracTickets for help on using tickets.